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1 | \section{\class{wxThreadHelper}}\label{wxthreadhelper} |
2 | ||
3 | The wxThreadHelper class is a mix-in class that manages a single background | |
4 | thread. By deriving from wxThreadHelper, a class can implement the thread | |
5 | code in its own \helpref{wxThreadHelper::Entry}{wxthreadhelperentry} method | |
6 | and easily share data and synchronization objects between the main thread | |
7 | and the worker thread. Doing this prevents the awkward passing of pointers | |
8 | that is needed when the original object in the main thread needs to | |
9 | synchronize with its worker thread in its own wxThread derived object. | |
10 | ||
11 | For example, \helpref{wxFrame}{wxframe} may need to make some calculations | |
12 | in a background thread and then display the results of those calculations in | |
13 | the main window. | |
14 | ||
15 | Ordinarily, a \helpref{wxThread}{wxthread} derived object would be created | |
16 | with the calculation code implemented in | |
17 | \helpref{wxThread::Entry}{wxthreadentry}. To access the inputs to the | |
18 | calculation, the frame object would often to pass a pointer to itself to the | |
19 | thread object. Similiarly, the frame object would hold a pointer to the | |
20 | thread object. Shared data and synchronization objects could be stored in | |
21 | either object though the object without the data would have to access the | |
22 | data through a pointer. | |
23 | ||
24 | However, with wxThreadHelper, the frame object and the thread object are | |
25 | treated as the same object. Shared data and synchronization variables are | |
26 | stored in the single object, eliminating a layer of indirection and the | |
27 | associated pointers. | |
28 | ||
29 | \wxheading{Derived from} | |
30 | ||
31 | None. | |
32 | ||
33 | \wxheading{Include files} | |
34 | ||
35 | <wx/thread.h> | |
36 | ||
37 | \wxheading{See also} | |
38 | ||
a1d8baa9 | 39 | \helpref{wxThread}{wxthread} |
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40 | |
41 | \latexignore{\rtfignore{\wxheading{Members}}} | |
42 | ||
43 | \membersection{wxThreadHelper::wxThreadHelper}\label{wxthreadhelperctor} | |
44 | ||
45 | \func{}{wxThreadHelper}{\void} | |
46 | ||
47 | This constructor simply initializes a member variable. | |
48 | ||
6d06e061 | 49 | \membersection{wxThreadHelper::m\_thread}\label{wxthreadhelpermthread} |
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50 | |
51 | \member{wxThread *}{m\_thread} | |
52 | ||
53 | the actual \helpref{wxThread}{wxthread} object. | |
54 | ||
6d06e061 | 55 | \membersection{wxThreadHelper::\destruct{wxThreadHelper}}\label{wxthreadhelperdtor} |
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56 | |
57 | \func{}{\destruct{wxThreadHelper}}{\void} | |
58 | ||
59 | The destructor frees the resources associated with the thread. | |
60 | ||
61 | \membersection{wxThreadHelper::Create}\label{wxthreadhelpercreate} | |
62 | ||
63 | \func{wxThreadError}{Create}{\param{unsigned int }{stackSize = 0}} | |
64 | ||
65 | Creates a new thread. The thread object is created in the suspended state, and you | |
684761db | 66 | should call \helpref{GetThread()->Run()}{wxthreadrun} to start running |
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67 | it. You may optionally specify the stack size to be allocated to it (Ignored on |
68 | platforms that don't support setting it explicitly, eg. Unix). | |
69 | ||
70 | \wxheading{Return value} | |
71 | ||
72 | One of: | |
73 | ||
74 | \twocolwidtha{7cm} | |
75 | \begin{twocollist}\itemsep=0pt | |
76 | \twocolitem{{\bf wxTHREAD\_NO\_ERROR}}{There was no error.} | |
77 | \twocolitem{{\bf wxTHREAD\_NO\_RESOURCE}}{There were insufficient resources to create a new thread.} | |
78 | \twocolitem{{\bf wxTHREAD\_RUNNING}}{The thread is already running.} | |
79 | \end{twocollist} | |
80 | ||
81 | \membersection{wxThreadHelper::Entry}\label{wxthreadhelperentry} | |
82 | ||
83 | \func{virtual ExitCode}{Entry}{\void} | |
84 | ||
85 | This is the entry point of the thread. This function is pure virtual and must | |
86 | be implemented by any derived class. The thread execution will start here. | |
87 | ||
88 | The returned value is the thread exit code which is only useful for | |
89 | joinable threads and is the value returned by | |
90 | \helpref{GetThread()->Wait()}{wxthreadwait}. | |
91 | ||
fc2171bd | 92 | This function is called by wxWidgets itself and should never be called |
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93 | directly. |
94 | ||
95 | \membersection{wxThreadHelper::GetThread}\label{wxthreadhelpergetthread} | |
96 | ||
97 | \func{wxThread *}{GetThread}{\void} | |
98 | ||
99 | This is a public function that returns the \helpref{wxThread}{wxthread} object | |
100 | associated with the thread. | |
684761db | 101 |